feat: Enable transcription based on MUC config form (#1135)

Read room_metadata from the MUC config form, and enable transcription if
it is requested.

jicofo-common/pom.xml

@@ -103,6 +103,11 @@
       <groupId>org.glassfish.jersey.media</groupId>
       <artifactId>jersey-media-json-jackson</artifactId>
     </dependency>
+    <dependency>
+        <groupId>com.fasterxml.jackson.module</groupId>
+        <artifactId>jackson-module-kotlin</artifactId>
+    </dependency>
+
     <!-- https://mvnrepository.com/artifact/com.github.spotbugs/spotbugs-annotations -->
     <dependency>
       <groupId>com.github.spotbugs</groupId>

jicofo-common/src/main/kotlin/org/jitsi/jicofo/xmpp/muc/ChatRoom.kt

@@ -62,6 +62,9 @@ interface ChatRoom {
      *  Read from the MUC config form. */
     val participantsSoftLimit: Int?
 
+    /** Whether the room is configured to require transcription. */
+    val transcriptionRequested: Boolean
+
     val debugState: OrderedJsonObject
 
     /** Returns the number of members that currently have their audio sources unmuted. */

jicofo-common/src/main/kotlin/org/jitsi/jicofo/xmpp/muc/ChatRoomImpl.kt

@@ -156,6 +156,15 @@ class ChatRoomImpl(
             }
         }
 
+    override var transcriptionRequested: Boolean = false
+        private set(value) {
+            if (value != field) {
+                logger.info("transcriptionRequested is now $value.")
+                field = value
+                eventEmitter.fireEvent { transcriptionRequestedChanged(value) }
+            }
+        }
+
     private val avModerationByMediaType = ConcurrentHashMap<MediaType, AvModerationForMediaType>()
 
     /** The emitter used to fire events. */
@@ -278,10 +287,25 @@ class ChatRoomImpl(
     private fun parseConfigForm(configForm: Form) {
         lobbyEnabled =
             configForm.getField(MucConfigFormManager.MUC_ROOMCONFIG_MEMBERSONLY)?.firstValue?.toBoolean() ?: false
-        visitorsEnabled =
-            configForm.getField(MucConfigFields.VISITORS_ENABLED)?.firstValue?.toBoolean()
-        participantsSoftLimit =
-            configForm.getField(MucConfigFields.PARTICIPANTS_SOFT_LIMIT)?.firstValue?.toInt()
+        visitorsEnabled = configForm.getField(MucConfigFields.VISITORS_ENABLED)?.firstValue?.toBoolean()
+        participantsSoftLimit = configForm.getField(MucConfigFields.PARTICIPANTS_SOFT_LIMIT)?.firstValue?.toInt()
+        // Default to false unless specified.
+        val roomMetadata = configForm.getRoomMetadata()
+        if (roomMetadata != null) {
+            transcriptionRequested = roomMetadata.recording?.isTranscribingEnabled == true
+        }
+    }
+
+    private fun Form.getRoomMetadata(): RoomMetadata.Metadata? {
+        getField("muc#roominfo_jitsimetadata")?.firstValue?.let {
+            try {
+                return RoomMetadata.parse(it).metadata
+            } catch (e: Exception) {
+                logger.warn("Invalid room metadata content", e)
+                return null
+            }
+        }
+        return null
     }
 
     override fun leave() {

jicofo-common/src/main/kotlin/org/jitsi/jicofo/xmpp/muc/ChatRoomListener.kt

@@ -29,6 +29,7 @@ interface ChatRoomListener {
     fun localRoleChanged(newRole: MemberRole) {}
     fun numAudioSendersChanged(numAudioSenders: Int) {}
     fun numVideoSendersChanged(numVideoSenders: Int) {}
+    fun transcriptionRequestedChanged(transcriptionRequested: Boolean) {}
 }
 
 /** A class with the default kotlin method implementations (to avoid using @JvmDefault) **/

jicofo-common/src/main/kotlin/org/jitsi/jicofo/xmpp/muc/RoomMetadata.kt

@@ -0,0 +1,54 @@
+/*
+ * Jicofo, the Jitsi Conference Focus.
+ *
+ * Copyright @ 2024-Present 8x8, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jitsi.jicofo.xmpp.muc
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import com.fasterxml.jackson.core.JsonParser
+import com.fasterxml.jackson.core.JsonProcessingException
+import com.fasterxml.jackson.databind.JsonMappingException
+import com.fasterxml.jackson.databind.MapperFeature
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+
+/**
+ * The JSON structure included in the MUC config form from the room_metadata prosody module in jitsi-meet. Includes
+ * only the fields that we need here in jicofo.
+ */
+@JsonIgnoreProperties(ignoreUnknown = true)
+data class RoomMetadata(
+    val type: String,
+    val metadata: Metadata?
+) {
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    data class Metadata(val recording: Recording?) {
+        @JsonIgnoreProperties(ignoreUnknown = true)
+        data class Recording(val isTranscribingEnabled: Boolean?)
+    }
+
+    companion object {
+        private val mapper = jacksonObjectMapper().apply {
+            enable(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS)
+            enable(JsonParser.Feature.STRICT_DUPLICATE_DETECTION)
+        }
+
+        @Throws(JsonProcessingException::class, JsonMappingException::class)
+        fun parse(string: String): RoomMetadata {
+            return mapper.readValue(string)
+        }
+    }
+}

jicofo-common/src/test/kotlin/org/jitsi/jicofo/xmpp/muc/RoomMetadataTest.kt

@@ -0,0 +1,84 @@
+/*
+ * Jicofo, the Jitsi Conference Focus.
+ *
+ * Copyright @ 2024-Present 8x8, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jitsi.jicofo.xmpp.muc
+
+import io.kotest.assertions.throwables.shouldThrow
+import io.kotest.core.spec.style.ShouldSpec
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import io.kotest.matchers.types.shouldBeInstanceOf
+
+class RoomMetadataTest : ShouldSpec() {
+    init {
+        context("Valid") {
+            context("With isTranscribingEnabled set") {
+                val parsed = RoomMetadata.parse(
+                    """
+                {
+                    "type": "room_metadata",
+                     "metadata": {
+                        "recording": {
+                            "isTranscribingEnabled": true,
+                            "anotherField": 123
+                        },
+                        "anotherField": {}
+                     }
+                }
+                    """.trimIndent()
+                )
+                parsed.shouldBeInstanceOf<RoomMetadata>()
+                parsed.metadata!!.recording!!.isTranscribingEnabled shouldBe true
+            }
+            context("With no recording included") {
+
+                val parsed = RoomMetadata.parse(
+                    """
+                {
+                    "type": "room_metadata",
+                     "metadata": {
+                        "key": {
+                            "key2": "value2"
+                        },
+                        "anotherField": {}
+                     }
+                }
+                    """.trimIndent()
+                )
+                parsed.shouldBeInstanceOf<RoomMetadata>()
+                parsed.metadata.shouldNotBeNull()
+                parsed.metadata?.recording shouldBe null
+            }
+        }
+        context("Invalid") {
+            context("Missing type") {
+                shouldThrow<Exception> {
+                    RoomMetadata.parse(
+                        """
+                        { "key": 123 }
+                        """.trimIndent()
+                    )
+                }
+            }
+            context("Invalid JSON") {
+                shouldThrow<Exception> {
+                    RoomMetadata.parse("{")
+                }
+            }
+        }
+    }
+}

jicofo/src/main/java/org/jitsi/jicofo/conference/JitsiMeetConferenceImpl.java

@@ -2336,6 +2336,11 @@ public void memberPresenceChanged(@NotNull ChatRoomMember member)
         {
         }
 
+        @Override
+        public void transcriptionRequestedChanged(boolean transcriptionRequested)
+        {
+        }
+
         @Override
         public void numAudioSendersChanged(int numAudioSenders)
         {

jicofo/src/main/java/org/jitsi/jicofo/jigasi/TranscriberManager.java

@@ -77,7 +77,8 @@ public class TranscriberManager
 
     /**
      * A single-threaded {@link ExecutorService} to offload inviting the
-     * Transcriber from the smack thread updating presence.
+     * Transcriber from the smack thread updating presence. It's important that requests are handled sequentially to
+     * prevent multiple jigasis being invited.
      */
     private final ExecutorService executorService = Executors.newSingleThreadExecutor();
 
@@ -125,20 +126,37 @@ private void memberPresenceChanged(@NotNull ChatRoomMember member)
         if (transcriptionStatusExtension != null
                 && TranscriptionStatusExtension.Status.OFF.equals(transcriptionStatusExtension.getStatus()))
         {
-            // puts the stopping in the single threaded executor
-            // so we can order the events and avoid indicating active = false
-            // while we are starting due to concurrent presences processed
-            executorService.execute(this::stopTranscribing);
+            active = false;
+            logger.info("detected transcription status being turned off.");
         }
         if (isRequestingTranscriber(presence) && !active)
         {
-            if (jigasiDetector == null)
+            tryToStart();
+        }
+    }
+
+    private void tryToStart()
+    {
+        if (jigasiDetector == null)
+        {
+            logger.warn("Transcription requested, but jigasiDetector is not configured.");
+            return;
+        }
+
+        if (active)
+        {
+            return;
+        }
+
+        executorService.execute(() -> {
+            if (active)
             {
-                logger.warn("Transcription requested, but jigasiDetector is not configured.");
                 return;
             }
-            executorService.execute(() -> this.startTranscribing(conference.getBridgeRegions()));
-        }
+
+            // We need a modifiable list for the "exclude" parameter.
+            selectTranscriber(2, new ArrayList<>(), conference.getBridgeRegions());
+        });
     }
 
     /**
@@ -159,13 +177,6 @@ private TranscriptionStatusExtension getTranscriptionStatus(Presence p)
      */
     private void startTranscribing(@NotNull Collection<String> preferredRegions)
     {
-        if (active)
-        {
-            return;
-        }
-
-        // We need a modifiable list for the "exclude" parameter.
-        selectTranscriber(2, new ArrayList<>(), preferredRegions);
     }
 
     /**
@@ -234,15 +245,6 @@ private void selectTranscriber(
         }
     }
 
-    /**
-     * Indicate transcription has stopped and sets {@link this#active} to false.
-     */
-    private void stopTranscribing()
-    {
-        active = false;
-        logger.info("detected transcription status being turned off.");
-    }
-
     /**
      * Checks whether the given {@link Presence} indicates a conference
      * participant is requesting transcription
@@ -275,5 +277,15 @@ public void memberPresenceChanged(@NotNull ChatRoomMember member)
         {
             TranscriberManager.this.memberPresenceChanged(member);
         }
+
+        @Override
+        public void transcriptionRequestedChanged(boolean transcriptionRequested)
+        {
+            if (transcriptionRequested)
+            {
+                logger.info("Transcription requested from the room.");
+                tryToStart();
+            }
+        }
     }
 }